Wildguzzi.com
General Category => General Discussion => Topic started by: ray bear on January 27, 2022, 10:43:33 PM
-
was a little set back when I found this , When I pulled the motor down I found excess use of silicone and maybe it wasn't a neutral cure silicone and the acid has attacked the head , Dont Know. maybe just poor manufacture. . Been a heavy diesel mechanic for 45 years and come across gaskets that have been plastered in some form of gunk too often, If you have good straight surfaces you dont need anything but a quality gasket unless the manufacturer calls for it. MTBW
(https://i.ibb.co/c27vQd0/IMG-1255.jpg) (https://ibb.co/c27vQd0)
baixar imagem do instagram (https://500pxdownload.com/)
(https://i.ibb.co/c1gb9Tn/IMG-1256.jpg) (https://ibb.co/c1gb9Tn)
-
Interesting that the head with the gasket ring issue has the odd wear pattern in the combustion zone as well, that the other head does not.
That engine may have been running differently on one side for a long time, or had some manufacturing challenges, as you noted, in that head.
-
was a little set back when I found this but have had a good look and will run it again hope doesnt create hot spots , When I pulled the motor down I found excess use of silicone and maybe it wasn't a neutral cure silicone and the acid has attacked the head , Dont Know. maybe just poor manufacture. If it gives me trouble in the future will just have to replace it. Been a heavy diesel mechanic for 45 years and come across gaskets that have been plastered in some form of gunk too often, If you have good straight surfaces you dont need anything but a quality gasket unless the manufacturer calls for it. MTBW
(https://i.ibb.co/c27vQd0/IMG-1255.jpg) (https://ibb.co/c27vQd0)
baixar imagem do instagram (https://500pxdownload.com/)
(https://i.ibb.co/c1gb9Tn/IMG-1256.jpg) (https://ibb.co/c1gb9Tn)
Whats the history of the bike. Looks like a head thats sat in water for a while. Not sure I buy the neutral cure silicon thing as it's not really an issue on engine parts and the chamber shows the same type of damage also. Seems like any silicon used was to try and seal the damage that was already there. Same as the chamber itself and tell-tale signs of heavy corrosion and in the exhaust port as well. Personally I'd get the head gasket surface welded and machined flat again. The chamber damage is liveable with but the compression ring sealing surface not really.
Ciao
-
Yes it wouldnt be too much of an ordeal to weld and machine, you've talked me into it Damn. Ive had the bike for 15 years and 70000ks and never had a head off in that time, I imported the bike from power motors IL .who would know its history.
-
Yes it wouldnt be too much of an ordeal to weld and machine, you've talked me into it Damn. Ive had the bike for 15 years and 70000ks and never had a head off in that time, I imported the bike from power motors IL .who would know its history.
Yea good decision, you'll sleep better knowing it's done right:)
Ciao
-
I thought there was real mice in there from your post subject.. I was going to advice you to hurry and get that thing on the dyno.. :evil:
-
Could have sat for a while in a damp environment, with the exhaust valve open in the one cylinder with the corrosion. Have had mice set up home in some of my old outboard motors. Mice pee the bed, making a very corrosive atmosphere where their nest is.
Larry
-
Are the initials on the heads yours Raybear? Maybe someone marked them before sending them to be worked on.
Mice built a nest in my truck heater fan box the other day. When it got down to 20F and the dog kept fogging the windshield I had to clean it out.
-
Would detonation do damage like that around the gasket? I know it can pit piston ring grooves.
-
That looks as if it could be a bit of detonation (pre-ignition)? Did you notice any pinking from that cylinder?
Edit: Oops, someone else had the same thought at the same time.
-
Would detonation do damage like that around the gasket? I know it can pit piston ring grooves.
I look’s like that to me and I think improper use of silicone was a main contributing factor. Probly caused hot spots leading to pre ignition that lead to detonation that eroded the aluminum.
Might be worth measuring the rod bearing shells with a bail mike to see how hammered out they are
-
must have pretty sharp…teeth? I know they get hungry
-
I would concur on the silicone sealant theory, silicone sealers give off acetic acid and may well have been the inital cause of corrosion. Moisture and lack of oxygen when sitting in storage and you have the perfect soup for the aluminum to degrade.My $.02 As per Pink Floyd........ "there's something in my head, but it's not me."
Paul B :boozing:
-
I would concur on the silicone sealant theory, silicone sealers give off acetic acid and may well have been the inital cause of corrosion. Moisture and lack of oxygen when sitting in storage and you have the perfect soup for the aluminum to degrade.My $.02 As per Pink Floyd........ "there's something in my head, but it's not me."
Paul B :boozing:
Yep, they make a silicone for use around electrical stuff that either doesn’t have acetic acid or less of it. A small spot of corrosion on the head could lead to a series of unfortunate events.
-
Could be detonation as its all inside the fire ring of the gasket and some around the guide and peeking out from under the valve seat, I just have to deal with it. Only on the right cylinder and nothing on the top of the piston which makes me think it happened before its last rebuild as it has cast bores so not original for a 73, maybe the piston looked like the head so replaced it and only that right head gasket with the excess of silicone as if they were trying to help a pre existing problem. I know for a fact it had chrome bores originally because when I cleaned the sludge trap it was full of chrome. {Just Lovely, where do these people come from. Really) and only one nice neat centre punch mark on the bung like factory. Hmm maybe they just replaced cylinders only and never removed crank. If only our bikes could talk to us. Ray
(https://i.ibb.co/wMBKd57/IMG-1258.jpg) (https://ibb.co/wMBKd57)
-
Could be detonation as its all inside the fire ring of the gasket and some around the guide and peeking out from under the valve seat, I just have to deal with it. Only on the right cylinder and nothing on the top of the piston which makes me think it happened before its last rebuild as it has cast bores so not original for a 73, maybe the piston looked like the head so replaced it and only that right head gasket with the excess of silicone as if they were trying to help a pre existing problem. I know for a fact it had chrome bores originally because when I cleaned the sludge trap it was full of chrome. {Just Lovely, where do these people come from. Really) and only one nice neat centre punch mark on the bung like factory. Hmm maybe they just replaced cylinders only and never removed crank. If only our bikes could talk to us. Ray
(https://i.ibb.co/wMBKd57/IMG-1258.jpg) (https://ibb.co/wMBKd57)
I ruled out the detonation theory when I saw the same issues in the exhaust port. My bet is still on a bike left sitting with water in the cylinder. You'll also notice the damage is noticeably worse on the lower side of the head when fitted to the engine, ie the spark plug side. So piston at or near TDC and water sitting in the cylinder.
Ciao
-
Ray, I know the Power brothers you got the bike from and may have seen your bike in N IL. They sold the shop & retired, one lived 15mi up the road by Rockford. He used to stop by my shop while out riding. Nice guys.
Most likely had LA Sleeve inserts matched to pistons. What I did for 2 of my 700's, cheaper than Nic.
These guys are very competent wrenches, owned a Guzzi/Yamaha shop a long time.
-
Appropriate thread title
Phil Irving 1947
(https://i.ibb.co/LQ0KHGJ/4-AEB6-CA1-3173-4-C7-F-BFCE-BFC6-D3809238.jpg) (https://ibb.co/LQ0KHGJ)
Shame you haven’t got orig piston, my guess is it would be a little worse than Phil speaks of here
Hole as big as a shilling, he says elsewhere
Chuck posted a pic of a G5 that did that, don’t remember if we got a head shot but might be good comparo
I’ve definitely seen similar
-
I'm backing if you use a fine pick and pick away at the raised bubbles in the chamber with the pin holes in them and the others you'll find corrosion under the surface.
Ciao
-
I have a head exactly like that , it came from a bike left outside for years before he sold it to me .
Thing actually ran okay , it wasn't until I took it apart for some other work that I noticed it , most
of the porosity wasn't visible because of the carbon build up . I'm suggesting it's not too big a deal , YMMV . Peter
-
I dont think it will be too much of a problem , after all they are a very forgiving motor, what you see is all inside the gasket area. I did my apprenticeship on Detroit 2 stroke diesels and due to very quick expansion and contraction of a 2 stroke cracked cylinder heads between the valves were a weekly thing but this is far simpler than metal stitching that was allways given to the poor apprentice. Ill ship this one out to the head guys and sit back and wait
-
I did my apprenticeship on Detroit 2 stroke diesels and due to very quick expansion and contraction of a 2 stroke cracked cylinder heads between the valves were a weekly thing .
Pics would be good, between valves on a 2 stroke.?
Eldo heads detonating around squish easier for my head.
-
Pics would be good, between valves on a 2 stroke.?
Eldo heads detonating around squish easier for my head.
Diesel
-
I'm admittedly inexperienced with Guzzi metallurgy and CYL head manufacturing or problems, but that looks like an issue with the casting. Some of that pitting looks pretty deep. Aluminum termites?
-
That looks as if it could be a bit of detonation (pre-ignition)? Did you notice any pinking from that cylinder?
You realize that detonation and pre-ignition are NOT the same.
-
I ruled out the detonation theory when I saw the same issues in the exhaust port. My bet is still on a bike left sitting with water in the cylinder. You'll also notice the damage is noticeably worse on the lower side of the head when fitted to the engine, ie the spark plug side. So piston at or near TDC and water sitting in the cylinder.
Good points.
-
You realize that detonation and pre-ignition are NOT the same.
I do NOW! 👍